In angiography blood vessels are displayed using diagnostic imaging methods, with a contrast agent generally being administered to the patient, in particular by means of injection, to show or emphasize the contrast in the images. Angiography methods are generally used to examine the vascular system of patients with arteriosclerosis. They allow the coronary vessels of a patient for example to be imaged so that a physician is then able to make a diagnosis.
Diseases of the vascular system, for example arteriosclerosis, are however frequently systemic diseases, i.e. patients who are examined for disease of the coronary vessels in a cardiac catheter laboratory for example, will quite probably also exhibit a peripheral manifestation of the disease, in the legs or limbs generally for example.
It is therefore in principle advantageous also to produce recordings of other body regions, for example the legs, during a cardiac examination, to enable a comprehensive assessment of the disease.
In order to record more extended, in particular longer, anatomical regions using angiography, the peripheral digital subtraction angiography method (extending to peripheral regions), also referred to as “perivision”, is frequently used. Here an anatomical mask image is subtracted in each instance from a vascular image filled with contrast agent (digital subtraction angiography or DSA) in a number of recording positions covering the entire region, to obtain a visualization of the vessels alone.
The workflow required for this is however relatively time-consuming and complex. On the one hand a total of three imaging passes has to be carried out, in particular a first test pass followed by a separate mask pass and a so-called fill pass (with contrast agent in the recording region), requiring not only a considerable time outlay but also numerous user interactions to control the method.
It is also frequently standard practice during the fill pass in order to monitor the contrast agent, to trigger the further movement of a detector from one recording position to the next manually, in order thus to be able to monitor the course of the contrast agent or the diffusion of the contrast agent in the body of the patient. This requires considerable experience on the part of the operator.